JP6834995B2 - Paper transfer device and image formation system - Google Patents

Description

The present invention relates to a paper transport device and an image forming system including the paper transport device.

A post-processing device for performing post-processing on the paper after image formation using an image forming device such as a copier may be connected to the image forming device. Further, a paper transport device may be connected between the image forming device and the post-processing device. The paper transport device transports the image-formed paper received from the image forming device to the post-processing device and delivers it. Patent Document 1 discloses an example of a conventional image forming apparatus including a paper conveying apparatus.

The conventional image forming apparatus disclosed in Patent Document 1 includes a transporting means for sandwiching and transporting paper, and a moving means for moving the transporting means along a direction intersecting the paper transporting direction (paper width direction). To be equipped. As a result, skew correction can be performed according to the state of the paper.

Japanese Unexamined Patent Publication No. 2016-183037

However, in the prior art disclosed in Patent Document 1, when a deviation occurs in the paper width direction, the conveying means is always moved in the paper width direction by a moving means in order to correct the deviation of the paper. Become. As a result, there has been a problem that it is not possible to cope with the high speed of paper transport.

The present invention has been made in view of the above points, and provides a paper transport device and an image forming system capable of coping with high-speed paper transport in correcting deviations in the paper width direction of paper. With the goal.

In order to solve the above problems, the paper transport device of the present invention includes a transport roller pair, a paper position detection unit, a shift drive unit, a shift amount detection unit, and a control unit. The transport roller pair transports the paper. The paper position detection unit detects the position of the paper with respect to a predetermined reference position in the paper width direction orthogonal to the paper transport direction. The shift drive unit moves the transport roller pair in the paper width direction to move the paper in the paper width direction. The misalignment detection unit detects the amount of paper misalignment with respect to the reference position in the paper width direction based on the amount of movement of the transport roller pair by the shift drive unit. The control unit controls the operation of the transport roller pair and the shift drive unit. Further, the control unit moves the paper in the paper width direction by the shift drive unit until the paper detected by the paper position detection unit reaches the reference position, and the paper misalignment amount detected by the misalignment amount detection unit is predetermined. When the number of times is within a predetermined reference value for a predetermined number of times in a row, the paper is not moved in the paper width direction for the next predetermined number of sheets.

Further, the paper transport device of the present invention includes a transport roller pair, a shift amount detection unit, a shift drive unit, and a control unit. The transport roller pair transports the paper. The misalignment detection unit detects the amount of misalignment with respect to a predetermined reference position in the paper width direction orthogonal to the paper transport direction. The shift drive unit moves the transport roller pair in the paper width direction to move the paper in the paper width direction. The control unit controls the operation of the transport roller pair and the shift drive unit. Further, when the paper misalignment amount detected by the misalignment detection unit exceeds a predetermined reference value, the control unit moves the paper to the reference position in the paper width direction by the shift drive unit, and the paper misalignment amount is the reference. If it is within the value, do not move the paper in the paper width direction.

According to the configuration of the present invention, when the amount of paper misalignment is within a predetermined reference value, the paper is not moved in the paper width direction. Therefore, in correcting the deviation of the paper in the paper width direction, the paper is not always moved in the paper width direction, but the paper is moved in the paper width direction as needed. This makes it possible to provide a paper transport device and an image forming system capable of coping with high speed of paper transport.

It is a front view which shows the structure of the image formation system of 1st Embodiment of this invention. It is a block diagram which shows the structure of the paper transport apparatus of 1st Embodiment of this invention. It is a partial schematic perspective view of the paper transport device of 1st Embodiment of this invention. It is a partial schematic top view of the paper transport device of 1st Embodiment of this invention. It is a partial top view which shows the state which the paper reached the place of the paper position detection sensor of the paper transport device of 1st Embodiment of this invention. It is a partial schematic top view which shows the state after shifting the paper in the paper width direction of the paper transporting apparatus of 1st Embodiment of this invention. It is a partial schematic top view which shows the state which returns the transport roller pair and the resist roller pair to the original position of the paper transport apparatus of 1st Embodiment of this invention. It is a partial schematic top view which shows the other state before the paper is shifted in the paper width direction of the paper transporting apparatus of 1st Embodiment of this invention. It is a flowchart which shows the example of the transfer process of the paper transfer apparatus of 1st Embodiment of this invention. It is a block diagram which shows the structure of the paper transport apparatus of 2nd Embodiment of this invention. It is a flowchart which shows the example of the transfer process of the paper transfer apparatus of the 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the following contents.

<First Embodiment>
First, the schematic configuration of the image forming system according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is an example of a front view showing the configuration of the image forming system S. The image forming system S includes an image forming device 101, a paper post-processing device 201, and a paper conveying device 1.

The image forming apparatus 101 is, for example, an inkjet recording apparatus, which is a so-called inkjet recording type printer. The image forming apparatus 101 includes a paper supply unit 102, a paper transport unit 103, a recording unit 104, a drying unit 105, a paper ejection unit 106, a decaler unit 107, and a main body control unit 108.

The paper supply unit 102 accommodates a plurality of sheets P in the paper feed cassette 102c and the manual paper ray 102t. At the time of printing, the paper supply unit 102 separates and feeds the paper P one by one from the paper feed cassette 102c or the manual paper lay 102t.

The paper transport unit 103 conveys the paper P fed from the paper supply unit 102 to the recording unit 104 and the drying unit 105, and further conveys the dried paper P to the paper ejection unit 106. The paper P for which the image formation has been completed is fed to the paper transport device 1 via the paper ejection unit 106. The paper transport unit 103 includes a first belt transport unit 103a and a second belt transport unit 103b. Further, the paper transport unit 103 includes a paper reversing unit 103r for switching the transport direction of the paper P and inverting the front and back of the paper when performing double-sided printing.

The recording unit 104 is arranged above the first belt transport unit 103a so as to face the paper P that is placed on the upper surface of the first belt transport unit 103a and is transported. The recording unit 104 includes a recording head which is a line-type inkjet head corresponding to each of the four colors of black, yellow, magenta, and cyan. The recording unit 104 sequentially ejects ink from the four-color recording head toward the paper P transported to the first belt transport unit 103a, and records a full-color image or a monochrome image on the paper P.

The drying unit 105 is arranged on the downstream side of the recording unit 104 in the paper transport direction. The drying portion 105 is placed above the second belt transport portion 103b so as to face the paper P that is placed and transported on the upper surface of the second belt transport portion 103b. The drying unit 105 dries the ink on the paper P while the paper P on which the ink image is recorded by the recording unit 104 is conveyed by the second belt conveying unit 103b.

The decaler portion 107 is arranged on the downstream side of the drying portion 105 in the paper transport direction. The decaler portion 107 receives the paper P to which the ink has been dried by the drying portion 105, and corrects the curl (warp) generated on the paper P.

The main body control unit 108 includes a CPU (not shown), an image processing unit, a storage unit, and other electronic components (not shown) and electronic circuits (not shown). The CPU controls the operation of each component provided in the image forming apparatus 101 based on the control program and data stored in the storage unit, and executes various processes related to the function of the image forming apparatus 101. The image processing unit performs image processing on the image data received from an external computer or the like in order to realize suitable recording. The storage unit is a combination of a non-volatile storage device such as a program ROM or a data ROM (not shown) and a volatile storage device such as a RAM.

The paper aftertreatment device 201 is on the downstream side of the paper transport device 1 in the paper transport direction, and is detachably connected to the side surface of the paper transport device 1. The paper post-processing device 201 includes a paper inlet 202, a paper ejection unit 203, a processing tray 204, a post-processing unit 205, and a post-processing control unit 206.

The paper inlet 202 is provided on the side surface facing the paper transport device 1 and opens. The paper P that has passed through the paper transport device 1 is fed into the paper aftertreatment device 201 through the paper entrance 202.

The paper ejection unit 203 extends from the paper inlet 202 to above the processing tray 204. The processing tray 204 is arranged below the downstream portion of the paper ejection unit 203. The processing tray 204 has an inclination that rises as the paper loading surface moves toward the downstream side in the paper transport direction. The paper P is post-processed in the processing tray 204. The paper P for which post-processing has been completed in the processing tray 204 is discharged to a discharge tray (not shown).

The post-processing unit 205 is arranged on the upstream side of the processing tray 204 in the paper transport direction. The post-processing unit 205 has, for example, a paper binding unit, and can perform binding processing (post-processing) on a bundle of paper P loaded on the processing tray 204 to bind the paper bundle.

The post-processing control unit 206 includes a CPU and other electronic circuits and electronic components (not shown). The post-processing control unit 206 is communicably connected to the main body control unit 108. The CPU receives a command from the main body control unit 108, controls the operation of each component provided in the paper post-processing device 201 based on the control program and data stored in the storage unit, and controls the operation of each component provided in the paper post-processing device 201. Execute various processes related to the function.

The paper transport device 1 is on the downstream side of the image forming device 101 in the paper transport direction, and is detachably connected to the side surface of the image forming device 101. A paper aftertreatment device 201 is detachably connected to the downstream side of the paper transport device 1 in the paper transport direction. The paper transport device 1 transports the image-formed paper P received from the image forming device 101 to the paper post-processing device 201. The paper transport device 1 is a relay transport unit for delivering the image-formed paper P to the paper post-processing device 201.

Subsequently, the details of the paper transport device 1 will be described with reference to FIGS. 2, 3 and 4 in addition to FIG. FIG. 2 is a block diagram showing the configuration of the paper transport device 1. FIG. 3 is a partial schematic perspective view of the paper transport device 1. FIG. 4 is a partial schematic top view of the paper transport device 1.

The paper transport device 1 includes a paper transport path 2, a transport roller unit 3, a resist roller unit 4, a paper detection sensor (paper detection unit) 5, a resist sensor 6, a paper position detection sensor (paper position detection unit) 7, and a transport control unit (paper transfer control unit). (Control unit) 10 is provided.

The paper transport path 2 extends from the carry-in inlet 2a to the carry-out port 2b, for example, in a straight line. The carry-in port 2a is adjacent to the paper ejection unit 106 of the image forming apparatus 101. The carry-out port 2b is adjacent to the paper entrance 202 of the paper aftertreatment device 201.

The transport roller portions 3 are provided at a plurality of locations along the transport direction of the paper transport path 2. The transfer roller unit 3 includes a first transfer roller unit 31, a second transfer roller unit 32, and a third transfer roller unit 33. The first transport roller section 31, the second transport roller section 32, and the third transport roller section 33 are arranged in order from the upstream side in the paper transport direction. Since all of these three transport roller portions 3 have the same configuration, they may be generally referred to as the "convey roller portion 3" in the following description unless it is particularly necessary to limit them. The transport roller unit 3 feeds the paper P and transports the paper P in the direction of the arrow X shown in FIGS. 3 and 4.

Each of the three transfer roller units 3 includes a transfer roller pair 3r, a transfer motor 3c, and a shift motor (shift drive unit) 3s. The transport roller pair 3r transports the paper P by sandwiching it between paper nip portions (not shown). The transfer motor 3c rotationally drives the transfer roller pair 3r.

The shift motor 3s moves the transport roller pair 3r in the paper width direction to move the paper P in the paper width direction (the arrow Y direction in FIG. 4). More specifically, the shift motor 3s moves the paper P in the paper width direction by moving the transport roller pair 3r sandwiching the paper P in the paper nip portion in the paper width direction. When the transport roller pair 3r is moved in the paper width direction, the transport roller pair 3r transports the paper P to the downstream side in the paper transport direction, and then the transport roller pair 3r is returned to the original position. The operations of the transfer motor 3c and the shift motor 3s are controlled by the transfer control unit 10.

The resist roller section 4 is arranged on the paper transport path 2 on the downstream side in the paper transport direction with respect to the transport roller section 3. The resist roller unit 4 includes a resist roller pair 4r, a resist motor 4c, and a shift motor (shift drive unit) 4s. The resist roller unit 4 uses a resist roller pair 4r and a resist motor 4c to temporarily stop the paper P transported in the paper transport path 2 and correct the diagonal feed of the paper P. Then, the resist roller unit 4 measures the timing with the operation of the paper aftertreatment device 201, and sends the paper P to the downstream side in the transport direction. The shift motor 4s moves the resist roller pair 4r in the paper width direction to move the paper P in the paper width direction (the arrow Y direction in FIG. 4). The operations of the resist motor 4c and the shift motor 4s are controlled by the transfer control unit 10. The resist roller pair 4r is also referred to as a transport roller pair when it comes to paper transport.

The paper detection sensors 5 are provided at a plurality of locations along the transport direction of the paper transport path 2. The paper detection sensor 5 includes a first paper detection sensor 51, a second paper detection sensor 52, and a third paper detection sensor 53. The first paper detection sensor 51, the second paper detection sensor 52, and the third paper detection sensor 53 are arranged in order from the upstream side in the paper transport direction to the center portion in the paper width direction of each of the three transport roller portions 3 on the upstream side in the paper transport direction. Be placed. Since all of these three paper detection sensors 5 have the same configuration, they may be generally referred to as the "paper detection sensor 5" in the following description unless it is particularly necessary to limit them.

The paper detection sensor 5 is arranged below the paper transport surface of the paper transport path 2. The paper detection sensor 5 includes, for example, an actuator (not shown) and a transmissive light sensor. The actuator comes into contact with the paper P passing through the paper transport path 2 and swings. The optical sensor detects that the swinging actuator blocks the optical path. The paper detection sensor 5 detects the presence or absence of paper P passing above the paper detection sensor 5. The detection signal of the paper detection sensor 5 is input to the transport control unit 10.

The resist sensor 6 is arranged at the center of the resist roller vs. 4r on the upstream side in the paper transport direction in the paper width direction. The resist sensor 6 has the same configuration as the paper detection sensor 5, and detects the presence or absence of the paper P passing above the paper detection sensor 5. The detection signal of the resist sensor 6 is input to the transport control unit 10.

The paper position detection sensor 7 is arranged at one end in the paper width direction on the downstream side of the resist roller vs. 4r in the paper transport direction. The paper position detection sensor 7 is arranged below the paper transport surface of the paper transport path 2. The paper position detection sensor 7 includes, for example, an actuator (not shown) and a transmissive light sensor (not shown). The actuator comes into contact with the paper P passing through the paper transport path 2 and swings. The optical sensor detects that the swinging actuator blocks the optical path. The paper position detection sensor 7 detects the position of the paper P passing above the paper P with respect to the reference position Rp (two-dot chain line in FIG. 4) in the paper width direction. The detection signal of the paper position detection sensor 7 is input to the transport control unit 10.

The transport control unit 10 includes a CPU 11, a storage unit 12, and other electronic components and circuits (not shown). The CPU 11 controls the operation of each component provided in the paper transport device 1 based on the control program and data stored in the storage unit 12, and executes various processes related to the functions of the paper transport device 1. The storage unit 12 is a combination of a non-volatile storage device such as a program ROM or a data ROM (not shown) and a volatile storage device such as a RAM.

Subsequently, the operation of the paper transport device 1 will be described with reference to FIGS. 5, 6, 7, and 8. FIG. 5 is a schematic top view of a portion of the paper transport device 1 showing a state in which the paper P reaches the position of the paper position detection sensor 7. FIG. 6 is a schematic top view of a portion showing a state after the paper P is shifted and moved in the paper width direction. FIG. 7 is a schematic top view of a portion showing a state in which the transport roller pair 3r and the resist roller pair 4r are returned to their original positions. FIG. 8 is a schematic top view of a portion showing another state before the paper P is shifted and moved in the paper width direction.

When the paper P that has passed through the paper nip portion of the resist roller vs. 4r reaches the position of the paper position detection sensor 7, the transport control unit 10 detects the position of the paper P with respect to the reference position Rp by using the paper position detection sensor 7. .. When the paper P is deviated from the reference position Rp, the transport control unit 10 moves the paper P in the paper width direction by the shift motors 3s and 4s until the paper P reaches the reference position Rp.

After correcting the diagonal feed of the paper P, the transport control unit 10 rotates the transport roller pair 3r and the resist roller pair 4r for a predetermined period to align the downstream end of the paper P in the paper transport direction with the position of the paper position detection sensor 7. Then, the transport control unit 10 detects the position of the paper P passing above the paper position detection sensor 7 with respect to the reference position Rp in the paper width direction.

When the paper position detection sensor 7 does not detect the paper P whose downstream end in the paper transport direction is aligned with the position of the paper position detection sensor 7 as shown in FIG. 5, the transport control unit 10 transfers the paper P as shown in FIG. The shift motors 3s and 4s move the entire paper P in the paper width direction so as to approach the reference position Rp until the paper reaches the reference position Rp. In other words, when the position of the end portion of the paper P on the reference position Rp side in the width direction of the paper P is deviated below the reference position Rp in FIG. 5, the transport control unit 10 has the width of the paper P. The paper P is moved upward in FIG. 5 until the position of the direction end reaches the reference position Rp.

At this time, as shown in FIG. 6, the transfer control unit 10 may move only the transfer roller pair 3r and the resist roller pair 4r holding the paper P in the paper width direction, or all the transfer roller pairs 3r and the resist. The rollers vs. 4r may be moved in the paper width direction.

When the paper P reaches the reference position Rp in the paper width direction, the transport control unit 10 feeds the paper P toward the carry-out outlet 2b of the paper transport path 2. Then, the transport control unit 10 returns the transport roller pair 3r and the resist roller pair 4r, which have been moved in the paper width direction until the paper P reaches the reference position Rp, to their original positions as shown in FIG. 7. In other words, the transfer control unit 10 moves the transfer roller pair 3r and the resist roller pair 4r downward in FIG. 7.

At this time, as shown in FIG. 7, the transport control unit 10 may return the transport roller pair 3r and the resist roller pair 4r to their original positions in order from the transport roller pair 3r on the most upstream side in the paper transport direction. All transport rollers vs. 3r and resist rollers vs. 4r may be returned to their original positions at the same time.

When the paper position detection sensor 7 detects the paper P whose downstream end in the paper transport direction is aligned with the position of the paper position detection sensor 7 as shown in FIG. 8, the transport control unit 10 shows in FIG. Until the paper P reaches the reference position Rp, the shift motors 3s and 4s move the entire paper P in the direction away from the reference position Rp in the paper width direction. In other words, when the position of the end portion of the paper P on the reference position Rp side in the width direction of the paper P is shifted to the upper side of the reference position Rp in FIG. 8, the transport control unit 10 has the paper P in the width direction. The paper P is moved to the lower side in FIG. 8 until the position of the end reaches the reference position Rp.

The transport roller unit 3 and the resist roller unit 4 of the present embodiment have a function as a displacement amount detecting unit that detects a paper displacement amount in the paper width direction when the paper P is moved in the paper width direction by the shift motors 3s and 4s. .. Therefore, the transport roller unit 3 and the resist roller unit 4 have a sensor such as an encoder for detecting the amount of movement of the paper P in the paper width direction. As a result, the transport roller unit 3 and the resist roller unit 4, which are the displacement amount detection units, detect the amount of paper displacement in the paper width direction based on the movement amounts of the transfer rollers 3r and the resist rollers 4r by the shift motors 3s and 4s. To do.

Then, when the amount of paper misalignment detected by the transport roller unit 3 and the resist roller unit 4, which are the transfer control unit 10 displacement amount detection units, is within a predetermined reference value, the paper P is not moved in the paper width direction. .. More specifically, when the amount of paper misalignment detected by the transfer roller unit 3 and the resist roller unit 4, which are the transfer control unit 10 displacement amount detection units, is within a reference value for a predetermined number of consecutive times. The paper P is not moved in the paper width direction for the next predetermined number of sheets. For example, the paper transport device 1 does not move the paper P in the paper width direction for the next 100 sheets when the amount of paper misalignment is within the reference value 10 times in a row. Then, after the elapse of the next 100 sheets, the amount of paper misalignment is detected again.

Subsequently, an example of the transfer process by the paper transfer device 1 will be described along the flow shown in FIG. FIG. 9 is a flowchart showing an example of the transfer process of the paper transfer device 1.

When the paper transport device 1 receives the paper P from the image forming apparatus 101, the paper transport device 1 starts the paper transport operation (start of FIG. 9).

In step # 101, the paper P is conveyed to the position of the paper position detection sensor 7 along the paper conveying direction. At this time, the transport control unit 10 controls the operations of the transport motor 3c and the resist motor 4c to transport the paper P to the position of the paper position detection sensor 7 along the paper transport direction.

In step # 102, it is determined whether or not the paper position detection sensor 7 is ON. Here, the state in which the paper position detection sensor 7 is ON is a state in which the paper position detection sensor 7 detects the paper P whose downstream end in the paper transport direction is aligned with the position of the paper position detection sensor 7. (See FIG. 8). On the other hand, the state in which the paper position detection sensor 7 is OFF is a state in which the paper position detection sensor 7 does not detect the paper P whose downstream end in the paper transport direction is aligned with the position of the paper position detection sensor 7 (FIG. 5). reference). If the paper position detection sensor 7 is ON (the paper P is being detected by the paper position detection sensor 7), the process proceeds to step # 103. If the paper position detection sensor 7 is OFF (the paper P is not detected by the paper position detection sensor 7), the process proceeds to step # 104.

In step # 103, the paper P is moved in the paper width direction away from the reference position Rp. At this time, the transport control unit 10 controls the operations of the shift motors 3s and 4s, and keeps the paper P in the paper width direction (for example, lower in FIG. 8) until the position of the widthwise end portion of the paper P reaches the reference position Rp. Move (to the side).

In step # 104, the paper P is moved in the paper width direction toward the reference position Rp. At this time, the transport control unit 10 controls the operations of the shift motors 3s and 4s, and keeps the paper P in the paper width direction (for example, the upper side in FIG. 5) until the position of the widthwise end portion of the paper P reaches the reference position Rp. To) move.

In step # 105, the amount of paper misalignment in the paper width direction is detected. The transfer roller unit 3 and the resist roller unit 4, which are the deviation amount detection units, detect the paper deviation amount in the paper width direction based on the movement amounts of the transfer rollers 3r and the resist rollers 4r by the shift motors 3s and 4s.

In step # 106, it is determined whether or not the amount of paper misalignment is within the reference value. If the amount of paper misalignment is within the reference value, the process proceeds to step # 107. If the amount of paper misalignment is not within the reference value, the process proceeds to step # 109.

In step # 107, it is determined whether or not the amount of paper misalignment is within the reference value for a predetermined number of times in a row. If the amount of paper misalignment is within the reference value for a predetermined number of times in a row, the process proceeds to step # 108. If the amount of paper misalignment is not within the reference value for a predetermined number of times in a row, the process proceeds to step # 110.

In step # 108, it is set that the paper P is not moved in the paper width direction during the next predetermined number of sheets. Then, in step # 111, the paper P is conveyed to the carry-out port 2b, and then the transfer process of the paper P is completed (end of FIG. 9).

In step # 109, that is, when the number of consecutive times in which the amount of paper misalignment is within the reference value has not reached the predetermined number of times, the number of consecutive times in which the amount of paper misalignment is within the reference value is added for one time. Then, in step # 111, the paper P is conveyed to the carry-out port 2b, and then the transfer process of the paper P is completed (end of FIG. 9).

Step # 110, that is, when the paper misalignment amount is not within the reference value for a predetermined number of consecutive times, the number of consecutive times in which the paper misalignment amount counted so far is within the reference value is reset. Then, in step # 111, the paper P is conveyed to the carry-out port 2b, and then the transfer process of the paper P is completed (end of FIG. 9).

As in the first embodiment, the paper transport device 1 uses the shift motors 3s and 4s to shift the paper P to the paper width until the paper P detected by the paper position detection sensor 7 by the transport control unit 10 reaches the reference position Rp. Move in the direction. At this time, the transfer roller unit 3 and the resist roller unit 4, which are the displacement amount detection units, detect the paper displacement amount based on the movement amounts of the transfer rollers 3r and the resist rollers 4r by the shift motors 3s and 4s. Then, when the amount of paper misalignment is within the reference value for a predetermined number of times in a row, the transport control unit 10 does not move the paper P in the paper width direction for the next predetermined number of sheets.

According to this configuration, in correcting the deviation of the paper P in the paper width direction, it is possible to provide a period during which the paper P is not moved in the paper width direction at intervals of a predetermined number of sheets. That is, the paper P is not always moved in the paper width direction, but the paper P is moved in the paper width direction as needed. This makes it possible to provide the paper transport device 1 and the image forming system S that can cope with the high speed of paper transport.

Here, the three paper detection sensors 5 measure the distance between the plurality of papers P that are continuously conveyed. Then, the transport control unit 10 does not move the paper P in the paper width direction when the distance between the paper P is shorter than a predetermined predetermined distance and the amount of paper misalignment is within the reference value. According to this configuration, when the paper transport device 1 performs paper transport at a speed higher than usual, the paper P can be prevented from moving in the paper width direction. Therefore, it is possible to further speed up the paper transfer.

Further, when the paper P is moved in the paper width direction by the shift motors 3s and 4s, the transport control unit 10 moves only the transport rollers 3r and the resist rollers 4r holding the paper P in the paper width direction. According to this configuration, it is possible to reduce the amount of control processing when moving the paper P in the paper width direction. Therefore, it is possible to further speed up the paper transfer. Further, the power consumption of the paper transport device 1 can be reduced.

Further, when the transfer control unit 10 returns the transfer roller pair 3r and the resist roller pair 4r moved in the paper width direction by the shift motors 3s and 4s to the original positions, the transfer roller pair 3r on the most upstream side in the paper transfer direction In order from, the transport roller pair 3r and the resist roller pair 4r are returned to their original positions. According to this configuration, the transport roller pair 3r and the resist roller pair 4r can be quickly returned to their original positions in order from the most upstream side transport roller pair 3r after the paper P has passed. Therefore, it is possible to further speed up the paper transfer.

<Second Embodiment>
Next, the paper transport device according to the second embodiment of the present invention will be described with reference to FIGS. 10 and 11. FIG. 10 is a block diagram showing a configuration of a paper transport device. FIG. 11 is a flowchart showing an example of the transfer process of the paper transfer device. Since the basic configuration of this embodiment is the same as that of the first embodiment described above, the components common to the first embodiment are given the same reference numerals or the same names as before to be described. It may be omitted.

The paper transport device 1 of the second embodiment includes the paper misalignment amount detection sensor 8 shown in FIG. The paper misalignment amount detection sensor 8 is arranged below the paper transport surface of the paper transport path 2.

The paper misalignment amount detection sensor 8 has, for example, a plurality of reflective light sensors (not shown). The plurality of reflective light sensors are arranged side by side in the paper width direction, for example, on one end side of the paper P in the paper width direction. The paper misalignment amount detection sensor 8 is a misalignment amount detecting unit that detects the amount of paper misalignment with respect to the reference position Rp at the edge of the paper P on the reference position Rp side in the paper width direction.

With this configuration, the paper misalignment amount detection sensor 8 may be provided instead of the paper position detection sensor 7. In the present embodiment, it is assumed that the paper misalignment amount detection sensor 8 is arranged on the upstream side in the paper transport direction with respect to the paper position detection sensor 7.

When the paper transport operation is started in the paper transport device 1 of the present embodiment (start of FIG. 11), the amount of paper misalignment is detected in step # 201. The paper misalignment amount detection sensor 8 which is a misalignment amount detecting unit detects the paper misalignment amount in the paper width direction before the paper P is conveyed to the paper position detection sensor 7.

In step # 202, the paper P is conveyed to the position of the paper position detection sensor 7 along the paper conveying direction.

In step # 203, it is determined whether or not the amount of paper misalignment is within the reference value. If the amount of paper misalignment is within the reference value, the process proceeds to step # 207. If the amount of paper misalignment is not within the reference value, the process proceeds to step # 204.

In step # 204, it is determined whether or not the paper position detection sensor 7 is ON. If the paper position detection sensor 7 is ON (the paper P is being detected by the paper position detection sensor 7), the process proceeds to step # 205. If the paper position detection sensor 7 is OFF (the paper P is not detected by the paper position detection sensor 7), the process proceeds to step # 206.

In step # 205, the paper P is moved in the paper width direction away from the reference position Rp. In step # 206, the paper P is moved in the paper width direction toward the reference position Rp.

In step # 207, the paper P is conveyed to the carry-out port 2b, and then the transfer process of the paper P is completed (end of FIG. 11).

As in the second embodiment, in the paper transport device 1, the paper misalignment amount detection sensor 8 which is a misalignment amount detecting unit directly detects the paper misalignment amount with respect to the reference position Rp in the paper width direction. Then, when the paper misalignment amount exceeds a predetermined reference value, the transport control unit 10 moves the paper P to the reference position Rp in the paper width direction by the shift motors 3s and 4s, and the paper misalignment amount is within the reference value. If, the paper P is not moved in the paper width direction.

According to this configuration, the amount of paper misalignment can be detected without moving the paper P in the paper width direction by the shift motors 3s and 4s. Then, when the amount of paper misalignment is within the reference value, it is possible to continue the paper transport without moving the paper P in the paper width direction by the shift motors 3s and 4s. This makes it possible to provide the paper transport device 1 and the image forming system S that can cope with the high speed of paper transport.

Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to this, and various modifications can be made without departing from the gist of the invention.

The present invention can be used in a paper transport device of an image forming apparatus and an image forming system including the paper transport device.

1 Paper transport device 2 Paper transport path 3 Transport roller section (displacement amount detection section)
3r transport roller vs. 3s shift motor (shift drive unit)
4 Resist roller part (displacement amount detection part)
4r resist roller pair (conveyor roller pair)
4s shift motor (shift drive unit)
5 Paper detection sensor 7 Paper position detection sensor (paper position detection unit)
8 Misalignment detection sensor (deviation amount detection unit)
10 Transport control unit 101 Image forming device 201 Paper aftertreatment device P Paper Rp Reference position S Image forming system

Claims (5)

A pair of transport rollers that transport paper and
A paper position detection unit for detecting the position of the paper with respect to a predetermined reference position in the paper width direction orthogonal to the paper transport direction, and
A shift drive unit that moves the transport roller pair in the paper width direction to move the paper in the paper width direction.
A shift amount detection unit that detects the amount of paper misalignment with respect to the reference position in the paper width direction based on the amount of movement of the transport roller pair by the shift drive unit.
A control unit that controls the operation of the transport roller pair and the shift drive unit,
With
The control unit moves the paper in the paper width direction by the shift drive unit until the paper detected by the paper position detecting unit reaches the reference position, and the paper misalignment amount detected by the misalignment amount detecting unit is measured. A paper transport device characterized in that the paper is not moved in the paper width direction for the next predetermined number of sheets for a predetermined number of times in a row and within a predetermined reference value. Equipped with a paper detector for measuring the distance between multiple sheets that are continuously conveyed.
The control unit is characterized in that the paper is not moved in the paper width direction when the distance between the papers is shorter than a predetermined predetermined distance and the amount of the paper misalignment is within the reference value. The paper transport device according to claim 1. With a plurality of the transport roller pairs arranged in the transport direction,
The first or second aspect of the present invention, wherein the control unit moves only the transport roller pair that holds the paper in the paper width direction when the paper is moved in the paper width direction by the shift drive unit. The paper transport device described. With a plurality of the transport roller pairs arranged in the transport direction,
When the transfer roller pair moved in the paper width direction by the shift drive unit is returned to the original position, the control unit sets the transfer roller pair in order from the transfer roller pair on the most upstream side in the transfer direction. The paper transport device according to any one of claims 1 to 3, wherein the paper transport device is returned to the position of. The paper transport device according to any one of claims 1 to 4.
An image forming apparatus connected to the paper conveying device, which forms an image on the paper and feeds the formed paper to the paper conveying device.
An image forming system characterized by comprising.

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